I was planning ahead to start a mage and checked out the possible enchantments. To start with, I would assume most of the time the mage is not using weapons or a shield ... at least, that is if he wants to maximize any of the destruction, restoration, etc. spells. That leaves 6 items of gear. If you don't have the dual-enchanting perk, then I'd imagine that the helm, armor, neck and ring would have all destruction or a combination of destruction, conjuration, restoration, etc. That leaves the gloves and boots. The boots seem to be limited to a resist enchant (frost, fire, etc.) and the gloves fortify magicka.

So, picturing a mage with destruction in one hand and restoration in the other ... the mage is starting out at a real disadvantage in survival. I remember starting one, early on, and having tons of trouble surviving a frostbite spider at lvl8.

All this said, it appears that enchanting is the most essential skill to race through to get the double enchanting perk.

You can go far with enchanting, but resist enchants on the boots are not decent at all.

Much better to use the boots and gloves for Fortify Carry Weight.

Also you'll never go through an entire dungeon with restoration in one hand and destruction in the other. In combat mages always switch around spells. Summon a few atronachs, then throw up an Oakflesh, and then pull out dual Firebolts, then when the fight is over dual Healing.

That won't help you in a fight.

Bah, if you got hit you didn't fight well enough. A mage who gets hit isn't a mage.

It's a corpse.

Now any professional dungeon delver and looter of mages-who-got-hit will tell you having extra carry weight is very important.

But you can swap your boots and gloves around whenever you want!

Much better to have the resists or fortifies, then swap to the haulage gear when you need it.